Female terminals, quite often fabricated as metallic stamped and formed members, are used in a wide variety of electrical connector applications ranging from conventional mateable connectors to plug-in connectors for printed circuit boards. The female terminals provide conductive receptacles for male terminal pins of a mating connector, for instance.
One typical type of female terminal is a stamped and formed female crimp terminal having a crimpable conductor engaging end and an opposed pin receiving mating end. The terminal is stamped from metal material and the mating end is formed or rolled into a generally cylindrical configuration dimensioned to resiliently engage a pin terminal inserted therein. The pin receiving mating end, due to its method of manufacture, includes a longitudinally extending slot defined by opposed edges of the metal from which the terminal is formed. The slot usually extends longitudinally inwardly from the mating end of the terminal to facilitate resilient deformation of the mating end in response to insertion forces of the pin terminal. An example of such a stamped and formed female terminal is shown in U.S. Pat. No. 3,621,445 to Horecky, dated Nov. 16, 1971 and assigned to the assignee of this invention.
Over the years, there simply has been provided a myriad of such female terminals as described above for a wide range of applications. Yet, problems still arise in providing precise, calculatable insertion forces for the pin terminal in the female terminal, as well as preventing damage to the pin terminal which could effect the characteristics of the circuit through the terminals. This is particularly true with the ever increasing tendency of miniaturization in the electrical/electronics art.
More particularly, there are constant attempts to decrease the insertion forces involved while still maintaining good electrical connection between the female and male terminals. The most popular type of female terminal is shown in the Horecky patent, above, wherein the rolled cylindrical configuration of the female terminal is provided with one or more inwardly projecting resilient tongues formed from a cut-out in the cylindrical walls of the mating and of the female terminal. Such tongues actually are the parts of such female terminals which most affect the insertion force required on the mating pin terminal. In essence, such resilient tongues increase the insertion force of an otherwise unobstructed round or cylindrical receptacle provided by the mating end of the female terminal. Although the Horecky terminal has proven quite effective for its intended purposes, there are applications where an unobstructed mating end of the female terminal is more desirable.
Attempts at providing an unobstructed mating end of a female terminal wherein insertion forces are decreased yet controllable have involved such configurations as forming a second longitudinal slot which extends inwardly from the distal end of the mating end of the terminal to form sort of a bifurcated mating end. Those configurations present considerable problems, particularly with miniature circuits, in creating additional edges which have a tendency to score or damage mating pin terminals. Such damage also is possible with female terminals employing inwardly directed resilient tongues, as described above.
This invention is directed to solving the above problems and satisfying the need of a new female terminal which has an unobstructed pin receiving mating end, yet the terminal is provided with means for decreasing the insertion force required on the pin terminal.